Cobra Exhaust Tuning Recommendation

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

lilredrooster

Well-Known Member
Joined
Jul 16, 2013
Messages
117
Reaction score
7
Location
Perth Australia
Looks like the Manufacturer recommends that the Cobra Exhausts require re-jetting and tuning......... Does not seem that many get done!!!......


Yamaha Cobra Exhaust Website link below:

https://cobrausa.com/yamaha/v_max_85_07/motorcycle_exhausts/slip_ons/slip_on_slashcut/2168SC/

VMax Cobra Exhaust Fitting Instructions (See Attached)

Cobra Fitting Instructions Quote "IMPORTANT: It is recommended that you re-jet your bike with a Cobra Jet Kit, available from Cobra part #92-2168."

Recommended Cobra Jet Kit # 92-2168 Instructions & Parts List (See Attached)

Cobra Jet Kit # 92-2168 appears to have been developed by Dynojet.


 

Attachments

  • VMax Cobra Exhaust Instructions 2168SC.pdf
    25 KB · Views: 8
  • Cobra Jet Kit No 92-2168 Recommended with Exhausts.pdf
    96.3 KB · Views: 13
Recommended Cobra Jet Kit # 92-2168 Instructions & Parts List (See Attached)

Yamaha VMax 1200 Dynojet Stage 1 Jet Kit Instructions & Parts List (See Attached)


Interesting that many of the parts listed are shared in both kits......


Very Interested in any resident carb guru/enthusiasts thoughts/opinions on the suggested PAJ Pilot Air Jet modifications/changes......... :ummm:
 

Attachments

  • Cobra Jet Kit No 92-2168 Recommended with Exhausts.pdf
    96.3 KB · Views: 3
  • Dynojet Stage 1 Docs.pdf
    128.9 KB · Views: 6
The stock exhaust with stock front headers are good "generally" for around 113Hp for a stock bike on dyno. (given variations in dynos and bikes).

Looks like the Cobras with stock headers are around 100Hp. (seems few bikes with cobras have dyno numbers and fewer still install the cobra recommended jet kit).

The Cobra jet kit info is attached, it suggests quite a power gain, see graph and comments.


Questions that spring to mind are:

Are there any Vmax owners out there that have the Cobra exhausts running the Cobra jet kit??

Are there any Vmax/Cobra exhaust owners (stock-ish normally aspirated engine) out there that have achieved decent performance and how?

Is there any improvement (no matter how small) to be had, running the Cobra jet kit?

Anyone got any Dyno numbers with the Cobra exhausts and Cobra Jet kit?

Always grateful of any/all sensible thoughts and comments....

Enjoy the Ride..... Ride Safe..... :hippy biker:
 

Attachments

  • Cobra Jet Kit No 92-2168 Recommended with Exhausts.pdf
    96.3 KB · Views: 7
I cant find the Cobra Jet Kit 92-2168 anywhere. Also, my bike has a switch to keep Vboost open. Thoughts?
 
Gimmick on the switch to make it "feel" like it's faster. In fact it's slower.
The jet kit (like the exhaust) isn't worth having. You're going to give up approx 10% power when compared to stock mufflers (once you jet it back down). You can go down two main jets typically to help get it closer to right but it's still not going to regain any of that 10% lost power.
 
COBRA!



Stallone-Cobra.png

Every so-often, The Cobra rears its head. It's not his venom which places you in-peril, it's his bad breath.
 
Last edited:

Latest posts

Back
Top